CDC, states weigh usefulness of school closures

May 4, 2009 (CIDRAP News) – The Centers for Disease Control and Prevention (CDC) signaled today that it will change its current recommendation—which is to close schools for at least 2 weeks when a confirmed case of novel H1N1 swine flu is found among students—as health officials in the Seattle area and Minnesota scaled back their guidance to reflect more of a seasonal influenza approach.

Acting CDC director Dr. Richard Besser said in a press briefing that the virus is so widespread in the United States that "closing the schools as a means of not letting [the novel flu] spread through the community is not very effective."

"I would expect that as we get more information we will be looking to revise that guidance," he said.

The CDC's advice to close schools for 2 weeks has been "very aggressive—you may only get one chance to get out in front of a new infectious disease," Besser said. But the rapid spread of the virus across the country, plus information from multiple locations that the spectrum of disease is about as severe as average seasonal flu, has caused the agency to reconsider.

Therefore, he said, the CDC is considering changing its advice from automatically closing schools to asking schools and parents to weed out sick children and individually send them home for at least a week.

That procedure is already followed in Canada and in Seattle, which "asks people to really push hard on personal responsibility," Besser said, and today Minnesota followed suit. Health and education officials in that state released updated school closure guidance that asks parents and teachers to identify and isolate children who have a fever and a recent onset of flu-like symptoms.

Besser said that, in those areas, parents are asked to check their children in the morning, and, if they are sick or are starting to feel a little sick, to keep them home for a full 7 days, even if they start to feel better before that period is up. In addition, schools and individual teachers are asked to take a close look at children as they arrive in the morning and to send them home if the school believes they are developing illness—for 7 days or until they are proven not to have flu.

Public Health Seattle and King County, in its revised school closure guidance posted yesterday, said its policy change is an enhanced version of the approach it uses for seasonal influenza and is based on what is known about the new influenza virus and its spread. The guidance notes that the new strain, already spread widely, will continue for some time and that illness severity doesn't appear to be greater than typical seasonal influenza.

"Individualized school closure based on reports of diagnosed cases is less effective, in addition to being impractical, as a control measure," the Seattle-King County health department said. However, officials added that, consistent with seasonal influenza policy, some schools might be closed if large numbers of students or faculty become ill.

As the outbreak progresses, laboratory diagnosis will identify a shrinking proportion of cases, as testing demand exceeds capacity and many people who have mild infections won't see their doctors. "Closing schools where cases happen to be diagnosed while leaving most schools with undiagnosed cases open does not make sense as an ongoing influenza control strategy in our community," the department said.

Public Health Seattle and King County has several tools for schools and parents on its Web site, including a guide for parents on when to keep a child home from school, a flu symptom checklist, and advice on how to care for someone who has influenza.

Minnesota officials today unveiled similar guidance aimed at keeping students and staff with influenza symptoms out of schools, rather than routinely closing schools. They said in a statement that it's not possible to identify every case of novel influenza, because the symptoms mimic those of other respiratory diseases. "We also know that we have other acute viral respiratory infections circulating in Minnesota," they said in the statement.

"The fact that the novel influenza is currently behaving like regular flu does not mean we can relax," said Sanne Magnan, MD, Minnesota commissioner of health, in a press release today. "Seasonal flu is a major health concern in its own right. It's one of our leading causes of death, year in and year out."

Schools that have a confirmed novel influenza case have three options: remain open with the individual isolated at home, close schools based on public health and community assessment, or close schools for a set number of days based on CDC guidance, which could change.

Minnesota officials also said they are developing enhanced school-based surveillance for influenza-like illnesses.